Table 2. Specific activity of ΔDi-4S from cartilage after in vivo labelling with [35S]cysteine.
Labelled cysteine was injected in dtd and wild-type mice; after 24 h, mice were killed and GAGs from cartilage of the femoral heads and from skin were purified for disaccharide analysis. After digestion with chondroitinase ABC and ACII, disaccharides were analysed by HPLC and the amount of 35S activity associated with ΔDi-4S was measured. The specific activity (dpm/nmol) was normalized to blood radioactivity and to the body weight of the animals. The results shown, which are the means±S.D. for four separate mice, demonstrate that sulfate recruitment from the catabolism of cysteine is active in cartilage in vivo. *P<0.05.
| Specific activity (dpm/nmol)/(dpm in blood/body weight) | ||
|---|---|---|
| Cartilage* | Skin | |
| dtd | 0.0161±0.0018 | 0.0449±0.0197 |
| Wild-type | 0.0101±0.0012 | 0.0218±0.0068 |